Potassium, Random, Urine
Use
Potassium (K+) is the major intracellular cation with important functions in the body, including regulation of neuromuscular excitability, heart contractility, intracellular fluid volume, and hydrogen ion concentration. The kidneys are responsible for regulating potassium levels, with most filtered potassium being reabsorbed in the proximal tubules. The test is useful for determining the cause of hyper- or hypokalemia, and helps in assessing renal function particularly distal nephron function in potassium excretion.
Special Instructions
The test utilizes indirect potentiometry via an ion-selective electrode (ISE) for measurement. This method is sensitive to the concentration of ions in the urine sample. No specific patient preparation is detailed, but proper specimen collection without preservatives is highlighted.
Limitations
The ion-selective electrodes used in this test are selective for potassium ions, but may be affected by other monovalent cations. Interference from other ions is unlikely under physiological conditions, but should be considered if abnormal results are obtained.
FDA ApprovedNew York Approved
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 2828-2
- 2828-2
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
4 mL
Minimum Volume
1 mL
Container
Plastic, 5-mL tube
Collection Instructions
Collect a random urine specimen. Do not add preservatives.
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 30 days |